Yes. Some say that is a sign of good seed, but I know that while I like to see grinning seed, seed that isn't grinning isn't necessarily anything but awesome! Grinning seed normally comes from being stratified in the ground or above ground and exposed to moisture. Seed stratified above ground in a more modern fashion will not be grinning, but can still have very high viability.
For instance, the seed I sell comes from a commercial farm in Ontario. It is stratified above ground without moisture. The moisture in the sand is all it needs and it commonly tests in the low to mid 90% in viability tests. But, you will never see a grinning seed in the bunch.
So the question becomes why stratify above ground. First, they have the facilities to do so. When the seed is picked in late August, it is depulped and treated and mixed with sand. The sand/seed mix is placed into plastic totes and put into cold storage. After the weather gets cold enough, they turn off the cooler and leave the seed in there to moderate the temperatures. This avoids dipping very low at night which can cause rust. In the spring, when things start to warm, the totes containing the sand and seed are moved into an open air barn. They stay there, still no water being added, until they are ready to be planted in early August. At that time, they are soaked in bleach water over night to hydrate (they typically float out of the box). The seed still floating is discarded and it is spread out to surface dry so it will flow through the planter. A viability test is performed and the seed is treated with a fungicide and planted. With the exception of this past year, I've had nothing but stellar germination from this seed.
Your next question is why no water? The reason for that is the belief that adding moisture adds risk of disease. As long as very good results are being had without adding water, why take the chance of increased disease in the box by adding it at all? Especially when the only draw back is there will be no grinning seed.
